The present invention relates to the matching of shock waves to particular conditions inherent in a human being, the shock waves being provided for the destruction (comminution) of concrements within the body of such human being, and more particularly the invention relates to the matching of the production and transmission of such a shock waves into the body of a child.
A variety of publications, patents and patent applications deal with devices and methods for contactless comminution of concrements in bodies of human beings by means of ultrasonic shock waves; the method and equipment having been developed by the assignee corporation. Generally speaking, these known equipments include a pan, the bottom of which is configured as or contains an ellipsoidal reflector for sound and ultrasonic waves. An ellipsoid has two focal points, and the arrangment is configured so that in one of these focal points a spark gap produces a shock wave to be refocused and effective in the other focal point upon proper positioning of the equipment vis-a-vis a concrement to be destroyed shock waves can indeed be concentrated such that a concrement being situated in the second focal point will disentegrate. The shock wave fronts are therefore focused by the ellipsoidal reflector into the second focal point, whereby particularly a precise position of the point of origin of the shock wave in one of the focal points ensures that the shock waves are reconcentrated in a geometrically well defined second focal area.
The positioning of the equipment vis-a-vis the concrement to be destroyed will therefore involve positioning of the equipment such that the concrement is in fact situated in that second focal point. The patient will be situated in relation to the pan so that indeed the concrement has the proper position for destruction. The destruction and walls, particularly the kidney stones.
The comminution as such is such that wave fronts of the shock wave impacting upon the concrement near the aforementioned second focal point will cause a portion or a kidney stone, to be ablated and split off a core, ultimately resulting in the total destruction of the stone to the extent that it is reduced to a plurality of relatively small parts which can be past through the urinary tract out of the body system without requiring operative procedure.
It should be noted, however, that the equipment as it was developed, and as it has been practiced, with significant success has been designed for treating adults because the problem of kidney stones is primarily a problem that arises in adults. However, this is not exclusively true. Children may also develop kidney stones, and it was found that the application of the equipment to minors involves certain problems. This involves basically the fact that the dimensions of body parts of a child are smaller in general so that the same equipment cannot be truly "focused" to the kidney stone within the body of a child in quite the same way focusing is permitted with respect to adults simply by external positioning of the reflecting and shock wave generating equipment. Moreover, it was found that particularly in the case of small children the lung may in fact be traversed by not quite but nearly concentrated shock waves or the lung may be affected by certain stray components of the shock wave field. This of course poses an intolerable situation.